Piston for internal combustion motors



Feb. 2, 1937. E. c. LONG PISTON FOR INTERNAL COMBUSTION MOTORS Filed May 4, 1933 Patented Feb. 2, 1,937

UNITED STATES PATENT 'OFJFICE' PISTON FOB INTERNAL COMBUSTION I MOTORS Elmer 0. Long, Grosae Pointe Park, Mich. Application May 4, 1933, Serial No. 669,316

s Claims. (Cl. 309-11) This invention relates to certain improvements in a piston and is a furthering of the invention set forth in my pending application filed September 9, 1932, Serial No. 632,325, for a piston for internal combustion motors the present invention having for one of its objects to provide improved means for supporting the resiliently flexible side of the. piston skirt. I

Another object of the invention is in providing 19 the skirt of the piston with an improved form oi resiliently flexible thrust side;

A iurther object of the invention is in providing the piston skirt with an improved resiliently flexible thrust side and a yieldable expansible 5 member, activeon the thrust side.

A still further object of theinvention is in providing the piston skirt on the pin boss sides of an improved construction whereby the pin bosses, when moved outward by expansion of the head,

' are prevented from being active on one of the thrust sides of the skirt.

Other and iurther objects will appear in the specification and be specifically pointed outin the appended claims, reference being had to the accompanying drawing, exemplifying the invention, and in which:

Figure 1 is a pin boss side elevation oi this improved piston.

Figure 2 is -a longitudinal vertical sectional go view taken approximately on the lineII -l'l'. of

Figure 3 is alongitudinal vertical sectional view taken approximately on the line III-HI oi Fig. 2.

as Figure 4 is an invertedend view oi-Fig. 1.

Figure 5 is a horizontal sectional viewtaken approximately on the line V-V oi Fig.2.

Figure 6 is an inverted horizontal sectional view taken approximately on the line V IVI of Fig. 3. 40 Referring by numerals to the accompanying drawing, this improved piston comprises a head I having a side wall 2 in which the piston ring recesses I are formed, and integral with the side wall I of the head, is the piston skirt 4 having a 45 power thrust side 5 and a compression thrust side I, and disposed between said thrust sides are the pin boss sides I.

The piston is of the conventional trunk type having a pin boss 6 inwardly extending from each 50 pin boss side I which. is integral with the side wall 2 oi. the head, the pin boss sides 1 being relieved on the outside by respective insets 9 formed thereon.

Each. pinboss side 1 of the piston skirt is pro-' 65 vided witli an approidmate L-shaped slot I which is formed or out through the thickness or each pin boss side I, the vertical extension ii of each slot i0 extending upwardly to the core opening I: formed aboveeach pin boss and the lower end 01' each vertical extension Ii joining a respective transverse extension II of respective slots ll, said transverse extensions each being i'ormed on the bottom of respective insets 9 and extending to one end oteach inset towards the power thrust side I of the piston skirt. 10 The vertical extension ii of each L-shaped slot Ill is cut into respective pin bosses 8, and each pin boss on one side is cut away from the skirt! as designated at M, as shown more clearly in Fig. 5 adjacent each vertical extension ll of the slots 10.

Each pin boss side i on one 'end is provided with a longitudinally extending slot i5, each slot i5 paralleling a respective vertical extension ii of the L-shaped slots it. Each slot It extends 2o irom the bottom of; respective insets 8, to and into the lower piston ring groove 3, where said slots I! join a transverse slot it which is formed in and cut through the thickness of the piston head walll. The transverse slot I6 is joined by a longitudinally extending slot l'i which is disposed intermediate the slots l5 and extends irom the lower end of the skirt 4, the formation of the slots 5,16 and I I providing a pair of adjacent tongue portions I8 on the compression thrust side 6 of the piston.

The slot i5 and the vertical extension I l of the L-shaped slots ID on each pin boss side, by reason 0;! them extending parallel to one another, form a supporting'leg IS on each pin boss side o! the piston for the support of the cylinder bearing portion 20 on each pin boss side beneath the transverse extension I3 of respective L- shaped slots l0, said legs also providing supports for the respective tongue portions 18 which are 40 separated from the head by the slot IS on the compression thrust side 6 of the skirt 4.

Joined at their ends with the power thrust side 5 and the compression side 6 respectively, 01' the skirt 4, are a pair of members 2| of web formation, said members 2i extending across the interior of the skirt at right-angles to the pin boss axis and being free from engagement with the pin bosses, each member 2! having an inter mediately disposed opening 22 01' larger diameter than the bearings oi the pin bosses 8, said openings being in alinement with said pin bosses.

Formed in each member 24 adjacent a respective tongue portion I8, is an opening 23, said openings being in alinement, and mounted in said openings is a bolt 24 having its head 25 engaging the outside of one of the members 2|. The other end of said bolt 24 is threaded at 26 and has an adjusting nut 21 thereon in engagement with the outside of the other member 2|, and mounted on said bolt between the members 2|, is a coil spring 23;

Pistons of this character are preferably made of an aluminum alloy having some resiliency and after machining and finishing this improved piston, the bolt 24 having the spring28 thereon, is adjusted to an engaging length with respect to the members 2| so as to permit the spring 28 to hold the tongue portions l8 yieldably apart such distance that the skirt diameters across the thrust sides and across the lower cylinder bearingportions 20 on the pin boss sides,'will be a required fit for the motor cylinder in which the piston is to be mounted.

In adjusting the bolt 24, the tightening thereof when pulling the tongue portions l8 towards each other, will also move the opposing portions 20 of the skirt on the pin boss sides inward from points adjacent the power thrust side, and the lower end. of each leg l9 by reason of being connected to the lower part of the skirt will also be pulled inward. The members .2| will fulcrum at 29 where they are joined with the power thrust sid 5 during adjusting of the bolt 24.

When the piston is operating in the cylinder of an internal combustion motor, the tongue portions |8 on the compression thrust side 6 of the piston skirt and the lower portions 20 of the skirt will be permitted to respond to both the expanding pressure of the piston and the cylinder wall pressure, the spring 24 obviously being compressed by the inward cylinder wall pressure, this inward movement of thetongue portions l8 and the portions 20 of the skirt, which is permitted by the spring 28, preventing seizing or scoring of the skirt in the cylinder.

When the cylinder and the piston become cool and the cylinder wall pressure against the skirt is relieved, the spring" which has been previously heat tested, will expand outwardly against the ends of the members 2| adjacent the tongue portions i8, thereby causing said tongue portions and the lower portions 20 of the skirt to keep in following contact with the cylinder wall. Obviously'the spring 28 will cause the tongue portions 8 and the portions 20 on the pin'boss sides to maintain resilient contact with the cylinder wall during changing thermal conditions, and in maintaining this resilient contact with the cylinder wall, it is clear that the power thrust side 5 will also be incontact with the. cylinder wall, the skirt of the piston therefore being provided with means whereby both piston-slap and seizing or scoring of the piston is prevented.

Inasmuch as the legs ISdepending from the side wall 2 of the head, supportthe compression thrust side 6 which is separated from the head and the portions 20 on the pin boss sides of the skirt which are separated from the pin boss sides I by the extension ii! of the L-shaped slot I 0, the transverse members 2| merely serve as thrust members or struts to the tongue portions l8 of the compression thrust side 6, in addition to said members 2| serving as fulcrum members for the tongue portions l8.

From the foregoing, it is obvious that the invention provides a piston having a skirt which is resiliently flexible on both the compression thrust side and on the pin boss sides beneath the pin bosses, the resiliently flexible cylinder engaging area. of the skirt therefore, extending approximately two-thirds of the skirt circumference, thus leaving the remaining approximate one-thirdoi the skirt circumference solid, as is afforded by the thrust side 5 being integral with the side wall 2 of the head. As the compression thrust side 6 of the skirt and the connecting cylinder bearing portions 20 maintain engagement with the cylinder wall by reason of the spring 28 on the bolt 24, it necessarily follows that the power thrust side 5 will maintain engagement with the cylinder wall by the cylinder ntting action of the tongue portions III of the compression thrust side 6.

'As the head of the piston is of smaller diameter than the skirt, expansion of the head across the pin boss diametenwill cause outward expanding movement of the pin bosses 8, but as the compression thrust side 6 and the cylinder bearing portions 20 are free from the pin bosses by the L-shaped slots I0, this outward expanding movement is prevented from becoming active on the compression thrust side, and as the pin boss sides I are relieved by the insets l, the pin boss sides I will be prevented from engaging the cylinder wall. i

The pin bosses 8 are reenforced by apair of centrally disposed webs, 30 which are formed integral therewith and extend upwardly on the inner periphery of the pin boss sides 1 and across the under side of the head. 7 i t The members or struts 2|, by reason of each of them having an opening 22 larger thanthe bearings of the pin bosses 8, do not engage the piston pin of the piston and therefore arefree to act on the tongue portions l8 without binding. 1

It is obvious that various changes may. be made in the details of construction without departing from the spirit of this invention, and it is therefore to be understood that this invention shown and described..

tion is not to be limited to the specific construc- What I claim is: 1. A piston comprising a head, a skirt having opposing thrust sides and pin bosses, said skirt being separated from the head on one of its thrust sides, supporting members extending from one thrust side to the otheryand :legs

formed in the skirt wall and being free fromengagement with said pin bosses and depending from the headfor the support of said separated.

thrust side.

2. A piston comprising a head, a skirt having opposing thrust sides and pin bosses, said skirt being separated from the head'on oneoi its thrust sides, supporting members free from engagement with the pin bosses extending from one thrust side to the other, and legs formed in the skirt wall and being free from engagement with said pin bosses and depending from thehead for .4. A piston comprising a head, a; skirt having opposing thrust sides and pin bosses, said skirt being separated from the head on one of its thrust sides, supporting members free from engagement with the pin bosses extending from one thrust side to the other, and legs formed in the skirt-wall and being free from engagement with said pinbosses and depending from the head for the support of said separated thrust side, said separated thrust side being longitudinally slotted, and a resiliently yieldable element interposed between said members.

5. A piston comprising a head, a skirt formed continuous with the head on one side, and separated irom the head by a transverse slot on its opposite side, pin bosses integral with the skirt, said separated side of the skirt being longitudinally slotted, transverse members extending from the separated side to the opposite side of, the skirt, resilient means interposed between said members adjacent the separated side 'of the skirt, and legs formed in the skirt depending from the head and being free from engagement with the pin bosses tor the support of said separated skirt side.

g ,8. A piston comprising a head having a sidewall, a skirtiormed continuous with the head on one side, and separated from the head on its opposite side, pin bosses integral with the skirt, said separated side of-the skirt being longitudinally slotted, transverse members extending from the separated side to the opposite side of the skirt, resilient means interposed between said members adjacent the separated side oi theskirt, and a leg depending from the side wall of the head between respective pin bosses and the separated skirt side. g

having a side wall and a skirt having one of its thrust sides '7. A piston comprising a head longitudinally slotted and separated from the head and providing adjacent thrust faces, pin' bosses, legs separatedirom said pin bosses depending from the side wall oi! the head for the support for said thrust faces, and a resilientlyyieldable element disposed across said thrust faces and being cooperable to separate said thrust faces.

8. A piston comprising 'a head having. a side wall and a skirt having one or its thrust sides ltuigitudinally slotted and "separated from ,the head and providing adjacent thrust races, pin

- bosses, legs depending from the side wall of the head and being separated from the pin bosses and said thrust faces for the support of the thrust faces, an adjustable tie member disposed across said thrust ;18668' and being cooperabletherewith, and a resiliently'yieldable element mounted on the-tie member having itsends disposed to separate said thrust faces. W

, 9'. A piston comprising a headlha'ving a mi 7 wall, a skirt and pin bosses, the skirt having op posing thrust sides, a pair of adjacent tongue portions in one of the thrust sides having parts which extend to they open end of the piston, and

a leg extending from the side wall or the head to the lower part of the skirt between each respective tongue portion and a respective ,pin boss,

said legs being free from engagement with the pin bosses and respective tongue portions.

10. A piston comprising a head having a side and respective tongue'portions, and a transverse member extending from each tongue portion to,

the other thrust side of the skirt.

11. A piston comprising a head having a side wall, a skirt and pin bosses, the 'skirt having opposing thrust sides, a pair of adjacent tongue portions in one of the thrust sides, a leg extending from the side wall of the headto the lower part of the skirt between each respective tongue I portionand a respective pin boss, said legs being free from engagement with the pin bosses and respective tongue portions, a transverse member extending from each tongue portion to the other thrust side of the skirt, and a resiliently yieldable element disposed between s'aidmembers adjacent the tongue portions.

12. A piston comprising a head and a skirt having opposed thrust sides, one of said thrust sides being slotted for flexibility and being separated from the head, pin'bosses, legs separated from the pin bosses and said slotted thrust-side and depending from the'head for the support of said'flexible thrust side, and a resiliently yieldable element disposed across said slotted thrust side. I

13. A piston having a skirt, pin bosses extend-.

ing from the skirt and the skirt having opposed thrust sides, a pair of adjacent tongue portions formed in one of the thrust sides, a leg iormed in the skirt on one side of each tongue por-t ;tion and separated therefrom, a transverse member extending from each tongue portion to the other thrust side of the skirt, aresiliently yieldable element disposed between said members adjacent the tongueportions', and'an L-shap'ed slot in the skirt on each pin boss side, in opposing relation from each other and disposed so that the horizont'albar of each slot extends beneath a respective pin boss.

EIMERQIDNQ 

